Overfeed I'm certain these need flushed

Hey family!! 2nd Grow. Growing 3 Plants. All about 5 weeks old. 16 hours on 8 hours off Light Cycle. Been about 10 days into there hps light. Going from 3 budget led bulbs which I knew I needed something stronger. Running a we fan to help air circulation. Another we fan at the bottom. One rotates left to right. And the other one is just more a less decoration but running anyway lol. Don't have a pH tester on me due to being in quarantine and lockdown so I'm just running usesual tap water. But cause we live rural our water comes straight from a water spring well I thought it shouldn't be to bad. But let me cut to the question are these over feed? I'm only still new to this but looks like plant lock out and nutrient burn and nitrogen defiancy. Noticed they're clawing more today when I put the light's on. So I want to know can I just flush them all tomorrow and just go back to straight water? Any help suggested would be amazing proud of this 2nd grow even if it is shit I don't want to lose these baby's. P.s my wife feed them 500ml per plant. So the only thing I can think of to save them is flush them out !!! Pictures below

The ph plays a big role....If tap water is the only way try checking the ph of it from the internet page/stats of the company that imports the water to you...The leaves look a bit droopy too...overwatering maybe?

Flushed it and it's looking way better

Took this photo just now she's perking again. Looks 10x better in my opinion after a good flush.